package cn.com.headfree.qynj.util;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class ShaUtil {
	/**
	    * 利用java原生的类实现SHA256加密
	    * @param str 加密后的报文
	    * @return
	    */
	    public static String getSHA256(String str){
	      MessageDigest messageDigest;
	     String encodestr = "";
	     try {
	      messageDigest = MessageDigest.getInstance("SHA-256");
	      messageDigest.update(str.getBytes("UTF-8"));
	      encodestr = byte2Hex(messageDigest.digest());
	     } catch (NoSuchAlgorithmException e) {
	      e.printStackTrace();
	     } catch (UnsupportedEncodingException e) {
	      e.printStackTrace();
	     }
	     return encodestr;
	    }
	    /**
	    * 将byte转为16进制
	    * @param bytes
	    * @return
	    */
	    public static String byte2Hex(byte[] bytes){
	     StringBuffer stringBuffer = new StringBuffer();
	     String temp = null;
	     for (int i=0;i<bytes.length;i++){
	      temp = Integer.toHexString(bytes[i] & 0xFF);
	      if (temp.length()==1){
	      //1得到一位的进行补0操作
	      stringBuffer.append("0");
	      }
	      stringBuffer.append(temp);
	     }
	     return stringBuffer.toString();
	    }
}
